A vehicle heat exchanger which includes, in addition to a high-temperature side radiator used for cooling an internal combustion engine (an engine), a low-temperature side radiator used for cooling an inverter for controlling a drive motor or cooling a supercharger, such as a turbocharger, is known conventionally. A vehicle heat exchanger disclosed in, for example, Patent Literature 1 includes, in addition to the high-temperature side radiator described above, a low-temperature side radiator used for cooling an inverter for controlling a drive motor. In the configuration disclosed in Patent Literature 1, in addition to the high-temperature side radiator and the low-temperature side radiator described above, a condenser used for a refrigeration cycle is provided in parallel. The high-temperature side radiator, the low-temperature side radiator, and the condenser are integrated and constitute an Engine Cooling Module (ECM), to improve mounting properties when mounting onto a vehicle. In the configuration disclosed in Patent Literature 1, the inverter increases the temperature of the coolant, and the coolant is supplied from the lower portion of the low-temperature side radiator to the low-temperature side radiator. Then, the coolant, which is subjected to heat exchange with air and is cooled, flows out from the upper portion of the low-temperature side radiator.